Ovarian teratomas are linked to anti N-methyl D-aspartate receptor encephalitis since 2005. They are a type of germ cell tumors, found primarily in young women between 10 to 30 years. Incidence is about 1.2–14.2 cases per 100,000 people per year. However, familial ovarian teratomas are extremely rare with no figures available on incidence. Hence evidence-based guidance on the most suitable imaging modality, interval/duration of follow up and the criteria for screening other family members are lacking. Recently a germline missense mutation, C262T, in exon 1 of the bone morphogenetic protein 15 (BMP15) gene on X chromosome was found to be a pathogenic variant for ovarian immature teratoma, providing a potential biomarker for genetic screening.